Minorities and women now account for a disproportionate number of new HIV infections. Neuropathy is the most common neurologic complication of HIV, occurring in up to 60% of patients with advanced disease. Neuropathy is commonly painful and can have a significant negative impact on quality of life. Recent clinical trials of treatment for neuropathic pain related to HIV have had disappointing results, raising the question of whether the study medications truly lack efficacy, or if the instruments used to measure pain were poorly suited to the population under study. Pilot data suggest there may be racial and ethnic differences in clinical manifestations of HIV-associated neuropathy, including pain. The goal of this project is to better define these differences and to explore their neuro-biologic and socio-cultural underpinnings. Specific aims are: 1. To determine whether there are differences between racial and ethnic groups in clinical and neurophysiologic features of HIV-associated neuropathy 2. To determine if commonly used pain scales adequately reflect the pain experience of minority, low-literacy patients with HIV-associated distal sensory polyneuropathy (HIV-DSP) 3. To determine whether autonomic neuropathy (AN) is prevalent in HIV-positive minorities 4. To determine whether the characteristic peripheral nerve and skin biopsy pathology of HIV-DSP in the HAART-era varies with race or ethnicity Retrospective analyses will be performed on data collected by the National NeuroAIDS Tissue Consortium and the CNS HIV Antiretroviral Effects Research Study. Going forward, predominantly minority patients will be recruited for detailed neurologic assessment including: administration of pain and symptom scales; detailed neurologic assessment and quantification of deficits using validated instruments; neurophysiologic testing (nerve conduction studies, quantitative sensory testing and autonomic testing); and skin biopsy. Peripheral nerve pathology will be studied using autopsy specimens from the Manhattan HIV Brain Bank.